Dendrimer-induced colloids towards robust fluorescent photonic crystal films and high performance WLEDs

Photonic crystals (PCs) have attracted great attention in recent years because of their vibrant structural colors. However, the poor mechanical stability of photonic crystals has severely limited their application. Here, we present an original strategy to construct a flexible and tough PC film composed of composite microspheres. These microspheres were prepared by coating CdSe@ZnS quantum dots on generation 3 polyamidoamine (G3 PAMAM) dendrimer-functionalized poly(styrene-methyl methacrylate-acrylic acid) (PS) microspheres via an in situ reaction. Benefiting from the strong coordination interactions among the dendrimer-functionalized microspheres, the mechanical robustness and the mechanical stability of the PC film were notably strengthened. In addition, taking advantage of the angle-independent characteristics of the PC beads, we applied them to improve the luminescence of a white LED. The PC beads were simply doped into the silicone and the light intensity of the WLED was enhanced with a full angle, significantly. This method may provide an efficient route for designing energy-saving WLEDs with high brightness.